7-pyrollyl 9-aminoacyl tetracycline compounds and methods of use thereof

ABSTRACT

A compound of formula (I):  
                 
 
     wherein:  
     A represents an aromatic 5 membered heterocycle, optionally containing, in addition to the nitrogen atom indicated in formula (I), one to three additional nitrogen atoms and optionally substituted by one or more groups “R” selected from  
     halogen,  
     —NRaRb,  
     C 1-6  alkyl,  
     C 2-6  alkenyl,  
     C 3-6  alkynyl,  
     aryl,  
     heteroaryl,  
     hydroxy,  
     —OC 1-6  alkyl,  
     formyl,  
     cyano,  
     trifluoromethyl,  
     —CHNORa,  
     —CO 2 Ra,  
     —CONRaRb,  
     —NRaC(O)Ra,  
     —NRaC(O)ORa,  
     —OC(O)NRaRb,  
     —OC(O)Ra,  
     —OC(O)ORa,  
     or a C 1-6  alkyl group substituted by one or more groups selected from hydroxy,  
     —NRaRb,  
     —OC 1-6  alkyl,  
     —SRa,  
     —CHNORa,  
     —CO 2 Ra,  
     —CONRaRb,  
     —NRaC(O)Ra,  
     —NRaC(O)ORa,  
     —OC(O)NRaRb,  
     —OC(O)Ra,  
     —OC(O)ORa  
     X represents —NRxRy or —OC 1-6  alkyl optionally substituted by one or more groups selected from hydroxy, methoxy, halogen, amino and trifluoromethyl.  
     Ra and Rb independently represent hydrogen or C 1-6  alkyl (preferably methyl);  
     R 1  represents hydrogen, C 1-6  alkyl or together R 1  and R 2  represent a CH 2  moiety;  
     R 2  represents hydrogen, —OC 1-6  alkyl, —O(O)C 1-6  alkyl or hydroxy;  
     R 3  represents hydrogen, hydroxy or together R 3  and R 1  represent a CH 2  moiety;  
     R 4  represents hydrogen, or C 1-6  alkyl, optionally substituted by one or more groups selected from hydroxy, methoxy, halogen, amino and trifluoromethyl;  
     Rx and Ry independently represent hydrogen, benzyl, C 3-6 cycloalkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 1-6  alkyl optionally substituted by one or more groups selected from hydroxy, methoxy, halogen, NRaRb and trifluoromethyl, —C 1-6  alkylcycloalkyl, —C 1-6  alkylheterocycle, C 1-6  alkylamino and C 1-6  alkylthio or together Rx and Ry form a heterocycle;  
     and pharmaceutically acceptable derivatives and solvates thereof.

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 10/411,872, filed Apr. 10, 2003, which is a continuation ofU.S. patent application Ser. No. 10/211,205, filed Aug. 2, 2002, whichclaims priority to European Patent Application Serial No. 01500064.9,filed on Mar. 13, 2001. The entire contents of each of theseapplications are hereby incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

[0002] The present invention relates to a novel class of chemicalcompounds and to their use in medicine. In particular, the inventionconcerns novel tetracycline derivatives, methods for their preparation,pharmaceutical compositions containing them and their use as antibioticagents.

BACKGROUND OF THE INVENTION

[0003] Tetracycline derivatives are known for treating bacterialinfections. However, there remains a need for tetracycline derivativesfor the treatment of Gram-positive, Gram-negative and community acquiredinfections. Moreover, there remains a need for tetracycline derivativeseffective against tetracycline resistant strains.

DETAILED DESCRIPTION OF THE INVENTION

[0004] The present invention provides compounds of formula (I):

[0005] wherein:

[0006] A represents an aromatic 5 membered heterocycle, optionallycontaining, in addition to the nitrogen atom indicated in formula (I),one to three additional nitrogen atoms and optionally substituted by oneor more groups “R” selected from

[0007] halogen,

[0008] —NRaRb,

[0009] C₁₋₆ alkyl,

[0010] C₂₋₆ alkenyl,

[0011] C₃₋₆ alkynyl,

[0012] aryl,

[0013] heteroaryl,

[0014] hydroxy,

[0015] —OC₁₋₆alkyl,

[0016] formyl,

[0017] cyano,

[0018] trifluoromethyl,

[0019] —CHNORa,

[0020] —CO₂Ra,

[0021] —CONRaRb,

[0022] —NRaC(O)Ra,

[0023] —NRaC(O)ORa,

[0024] —OC(O)NRaRb,

[0025] —OC(O)Ra,

[0026] —OC(O)ORa,

[0027] or a C₁₋₆ alkyl group substituted by one or more groups selectedfrom hydroxy,

[0028] —NRaRb,

[0029] —OC₁₋₆ alkyl,

[0030] —SRa,

[0031] —CHNORa,

[0032] —CO₂Ra,

[0033] —CONRaRb,

[0034] —NRaC(O)Ra,

[0035] —NRaC(O)ORa,

[0036] —OC(O)NRaRb,

[0037] —OC(O)Ra,

[0038] —OC(O)ORa

[0039] X represents —NRxRy or —OC₁₋₆ alkyl optionally substituted by oneor more groups selected from hydroxy, methoxy, halogen, amino andtrifluoromethyl.

[0040] Ra and Rb independently represent hydrogen or C₁₋₆ alkyl(preferably methyl);

[0041] R¹ represents hydrogen, C₁₋₆ alkyl or together R¹ and R²represent a CH₂ moiety;

[0042] R² represents hydrogen, —OC₁₋₆ alkyl, —O(O)C₁₋₆ alkyl or hydroxy;

[0043] R³ represents hydrogen, hydroxy or together R³ and R¹ represent aCH₂ moiety;

[0044] R⁴ represents hydrogen, or C₁₋₆ alkyl, optionally substituted byone or more groups selected from hydroxy, methoxy, halogen, amino andtrifluoromethyl;

[0045] Rx and Ry independently represent hydrogen, benzyl,C₃₋₆cycloalkyl, C₃₋₆alkenyl, C₃₋₆alkynyl, C₁₋₆ alkyl optionallysubstituted by one or more groups selected from hydroxy, methoxy,halogen, NRaRb and trifluoromethyl, —C₁₋₁₆ alkylcycloalkyl, C₁₋₆alkylheterocycle, C₁₋₆ alkylamino and C₁₋₆ alkylthio or together Rx andRy form a heterocycle;

[0046] and pharmaceutically acceptable derivatives and solvates thereof.

[0047] Compounds of formula (I) contain at least one asymmetric centre,denoted by *, and thus may exist as enantiomers or diastereoisomers. Itis to be understood that the invention includes each such isomer, eitherin substantially pure form or admixed in any proportion with one or moreother isomers of the compounds of formula (I). The preferredstereochemistry at the centre where R¹ and R² are substituents is whenR¹ is H, R³ is in the alpha-configuration (downwards). The preferredstereochemistry at the centre where R² is a substituent is alpha(downwards). The preferred stereochemistry at the centre where N(Me)₂ isa substituent in the ring is alpha (downwards).

[0048] The term “pharmaceutically acceptable derivative” as used hereinrefers to any pharmaceutically acceptable salt, or metabolically labilederivative of a compound of formula (I), for example a derivative of anamine group, which, upon administration to the recipient, is capable ofproviding (directly or indirectly) a compound of formula (I). It will beappreciated by those skilled in the art that the compounds of formula(I) may be modified to provide pharmaceutically acceptable derivativesthereof at any of the functional groups in the compounds of formula (I).Such derivatives are clear to those skilled in the art, without undueexperimentation, and with reference to the teaching of Burger'sMedicinal Chemistry And Drug Discovery, 5th Edition, Vol 1: PrinciplesAnd Practice, which is incorporated herein by reference. For examplecompounds of formula (I) may be N-alkylated in the presence offormaldehyde and an amine such as methylamine to give the correspondingMannich base adducts.

[0049] Salts and solvates of compounds of formula (I) which are suitablefor use in medicine are those wherein the counterion or associatedsolvent is pharmaceutically acceptable. However, salts and solvateshaving non-pharmaceutically acceptable counterions or associatedsolvents are within the scope of the present invention, for example, foruse as intermediates in the preparation of other, compounds of formula(I) and their pharmaceutically acceptable derivatives, and solvates.

[0050] Suitable salts according to the invention include those formedwith both organic and inorganic acids or bases. Pharmaceuticallyacceptable acid addition salts include those formed fromtrifluoroacetic, hydrochloric, hydrobromic, hydroiodoic, sulphuric,citric, tartaric, phosphoric, lactic, pyruvic, acetic, succinic, oxalic,fumaric, maleic, oxaloacetic, methanesulphonic, ethanesulphonic,p-toluenesulphonic, benzenesulphonic, and isethionic acids.Pharmaceutically acceptable base salts include ammonium salts, alkalimetal salts such as those of sodium and potassium, alkaline earth metalsalts such as those of calcium and magnesium and salts with organicbases such as dicyclohexyl amine and Nmethyl-D-glucamine.

[0051] Suitable solvates according to the invention include hydrates.

[0052] The term alkyl, as used herein to define a group or a part of agroup, unless otherwise stated, refers to a saturated straight orbranched alkyl chain containing from 1 to 6 carbon atoms. Examples ofsuch groups include without limitation methyl, ethyl, n-propyl,isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, neopentyl andhexyl.

[0053] The term alkenyl, as used herein to define a group or a part of agroup, unless otherwise stated, refers to a straight or branched alkenylchain containing from 2 to 6 carbon. Examples of such groups includewithout limitation 1-ethenyl, 1-propenyl, allyl(2-propenyl), 1-butenyl,2-butenyl, 2-pentenyl.

[0054] The term alkynyl, as used herein to define a group or a part of agroup, unless otherwise stated, refers to a straight or branched alkynylchain containing from 3 to 6 carbon. Examples of such groups includewithout limitation propynyl, butynyl or pentynyl.

[0055] The term cycloalkyl as used herein to define a group or a part ofa group, unless otherwise stated, refers to a saturated alkyl ring,containing from 3 to 6 carbon atoms. Examples of such groups includecyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0056] The term halogen refers to a fluorine, chlorine, bromine oriodine atom. Suitably the halogen atom is selected from chlorine,bromine or iodine, preferably chlorine or bromine. Chlorine is mostpreferred.

[0057] The term aryl group refers to an aromatic mono or bicylclic ringsystem comprising from 5 to 10 carbon atoms and heteroaryl group iswherein one or more of the carbon atoms is/are replaced by heteroatomsindependently selected from nitrogen, oxygen and sulfur.

[0058] The term alkylamino as used herein to define a group or a part ofa group, unless otherwise stated, refers to a saturated straight orbranched alkyl chain containing from 1 to 6 carbon atoms substituted byone or more amino groups. Examples of such groups include withoutlimitation methylamino and tert-butylamino.

[0059] The term alkylthio as used herein to define a group or a part ofa group, unless otherwise stated, refers to a saturated straight orbranched alkyl chain containing from 1 to 6 carbon atoms substituted byone or more thiol groups. Examples of such groups include withoutlimitation methylthio and tert-butylthio.

[0060] The term heterocycle, as used herein refers to a 3, 4, 5 or 6membered saturated or unsaturated heterocyclic ring containing at leastone heteroatom selected from nitrogen, oxygen or sulphur. Suitableexamples include without limitation tetrahydrofuran, furane, thiophene,pyridine, pyrrole, 2-pyrroline, 3-pyrroline, pyrrolidine, imidazole,2-imidazoline, imidazolidine, pyrazole, 2-pyrazoline, pyrazoline,pyrazolidine, aziridine, 1,2,3-triazole, 1,2,4-triazole,1,2,3-thiadiazole, piperidine, morpholine, thiomorpholine, andpiperazine. It will be appreciated by those skilled in the art that whenX represents NRxRy and together Rx and Ry form a heterocycle, theheterocycle will contain at least one nitrogen atom. Examples ofsuitable nitrogen containing heterocycles include, without limitation,pyrrole, 2-pyrroline, 3-pyrroline, pyrrolidine, imidazole, 2,imidazoline, imidazolidine, pyrazole, 2-pyrazoline, pyrazoline,pyrazolidine, aziridine, 1,2,3-triazole, 1,2,4-triazole,1,2,3-thiadiazole, piperidine, morpholine, thiomorpholine, andpiperazine.

[0061] Suitably, A represents pyrrole, pyrazole, 1,2,3-triazole,1,2,4-triazole and tetrazole.

[0062] Preferred substituents on A include ethoxycarbonyl,carboxaldehyde, cyano, dimethylaminomethyl, oxime and methyloxime.

[0063] Suitably, R² is selected from hydrogen, methoxy and hydroxy. Moresuitably, R² is selected from hydrogen and hydroxy. Conveniently, R² ishydroxy. Preferably, R² is hydrogen.

[0064] Suitably, R³ represents hydrogen or methyl. Conveniently, R³ ismethyl. Preferably, R³ is hydrogen.

[0065] Suitably, Ra and Rb independently represent hydrogen or methyl.Conveniently, Ra and Rb are methyl. Preferably, Ra and Rb are hydrogen.

[0066] Suitably, Rx and Ry independently represent hydrogen, benzyl,C₃₋₆cycloalkyl, C₃₋₆alkenyl, C₁₋₆alkyl optionally substituted by one ormore groups selected from hydroxy, methoxy, and NRaRb, —C₁₋₃alkylcycloalkyl, C₁₋₃alkylheterocycle, C₁₋₆ alkylamino and C₁₋₆alkylthio or together Rx and Ry form a heterocycle. More suitably, Rxand Ry independently represent hydrogen, benzyl, C₃₋₆ cycloalkyl, C₃₋₆alkenyl, C₁₋₆ alkyl, —C₁₋₃ alkylcycloalkyl, —C₁₋₃ alkylheterocycle, ortogether Rx and Ry form a heterocycle. Conveniently, Rx and Ryindependently represent hydrogen, benzyl, C₃₋₆ cycloalkyl, C₃₋₆ alkenyl,C₁₋₆alkyl, or together Rx and Ry form a heterocycle. More conveniently,Rx and Ry independently represent hydrogen, benzyl, C₃₋₆ cycloalkyl,C₃₋₆ alkenyl, and C₁₋₆alkyl.

[0067] Suitably the compound of formula (I) is derivatised from anatural tetracycline like compound. Examples of natural tetracyclinelike compounds include tetracycline, chlortetracycline, oxytetracycline,demeclocycline, methacycline, sancycline, doxycycline, and minocycline.Preferably the natural tetracycline like compound is selected fromsancycline and doxycycline, most preferably sancycline.

[0068] It is to be understood that the present invention covers allcombinations of suitable, convenient, and preferred groups describedhereinabove.

[0069] References herein after to compounds of the invention includecompounds of formula (I) and their pharmaceutically acceptablederivatives and solvates.

[0070] Examples of compounds of Formula (1) include.

[0071] 4S-(4aα,5aα,12aα)]-7-(1H-pyrrol-1-yl-3-carboxaldehyde)-4-(dimethylamino)-9-[[(N,N,-dimethylamino)acetyl]-amino]-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide.

[0072] As demonstrated in the assays described below the compounds ofthe present invention show activity against the most importantpathogens, including gram positive bacteria such as S. pneumoniae and S.aureus, and gram negative organisms such as H. influenzae, M.catarrhalis and E. coli. In addition, these compounds are active againstgram positive and gram negative tetracycline resistant, bacterialstrains, including those with resistance mediated by efflux pumps andribosome protection.

[0073] Accordingly, in a further aspect the present invention provides amethod for the treatment of a tetracycline compound responsive state ina subject, preferably a human, which comprises administering to thesubject an effective amount of a compound of formula (I) orpharmaceutically acceptable derivative or solvate thereof.

[0074] In the alternative, there is provided a compound of formula (I)or a pharmaceutically acceptable derivative or solvate thereof, for usein medical therapy, particularly, for use in the manufacture of amedicament for the treatment of a tetracycline compound responsivestate.

[0075] The term tetracycline compound responsive state includes a statewhich can be treated, prevented, or otherwise ameliorated by theadministration of a compound of formula (I) or pharmaceuticallyacceptable derivative or solvate thereof. Tetracycline compoundresponsive states include bacterial infections (including those whichare resistant to other tetracycline compounds), cancer, diabetes, andother states for which tetracycline compounds have been found to beactive (see, for example, U.S. Pat. Nos. 5,789,395; 5,834,450; and5,532,227). Compounds of the invention can be used to prevent or controlimportant human and veterinary diseases such as respiratory tractinfections, systemic infections and some local infections. Moreparticularly, compounds of the invention can be used to prevent orcontrol diarrhea, urinary tract infections, infections of skin and skinstructure, ear, nose and throat infections, wound infection, mastitisand the like. In addition, methods for treating neoplasms usingtetracycline compounds of the invention are also included (van derBozert et al., Cancer Res., 48:6686-6690 (1988)). In one embodiment, thetetracycline compound is used to treat a bacterial infection. In afurther embodiment, the tetracycline compound is used to treat abacterial infection that is resistant to other tetracycline antibioticcompounds.

[0076] For the avoidance of doubt, the term ‘treatment’ as used hereinincludes prophylactic therapy.

[0077] Bacterial, infections may be caused by a wide variety of grampositive and gram negative bacteria. The compounds of formula (I) areuseful as antibiotics against organisms which are resistant toother-tetracycline compounds. The antibiotic activity of the compoundsof formula (I) may be determined using the method discussed in theBiological Example below, or by using the in vitro standard brothdilution method described in Waitz, J. A., National Committee forClinical Laboratory Standards, Approved Standard M7-T2, vol. 10, no. 8,pp. 13-20, 2nd edition, Villanova, Pa. (1990).

[0078] The compounds of the invention may also be used to treatinfections traditionally, treated with tetracycline compounds such as,for example, rickettsiae; a number of gram-positive and gram-negativebacteria; and the agents responsible for lymphogranuloma venereum,inclusion conjunctivitis and psittacosis. The compounds of formula (I)may be used to treat infections of pneumococci, Salmonella, E. coli, S.aureus or E. faecalis.

[0079] The term effective amount of the compound of formula (I) is thatamount necessary or sufficient to treat or prevent a tetracyclinecompound responsive state. The effective amount can vary depending onsuch factors as the size and weight of the subject, the type of illness,or the particular tetracycline compound. One of ordinary skill in theart would be able to study the aforementioned factors and make thedetermination regarding the effective amount of the compound of formula(I) or a pharmaceutically acceptable derivative or solvate thereofwithout undue experimentation.

[0080] The invention also pertains to methods of treatment againstmicro-organism infections and associated diseases. The methods includeadministration of an effective amount of one or more compounds offormula (I) or a pharmaceutically acceptable derivative or solvatethereof to a subject. Preferably the subject is a mammal e.g., a human.

[0081] For human use, a compound of the formula (I) can be administeredas raw drug substance, but will generally be administered in admixturewith a pharmaceutically acceptable carrier selected with regard to theintended route of administration and standard pharmaceutical practice.

[0082] Accordingly, the present invention further provides apharmaceutical formulation comprising a compound of formula (I) or apharmaceutically acceptable derivative or solvate thereof; and one ormore pharmaceutically acceptable carriers.

[0083] The term pharmaceutically acceptable carrier includes substancescapable of being coadministered with the compounds of formula (I), andwhich allow performance of the intended function, e.g., treat or preventa tetracycline compound responsive state. Suitable pharmaceuticallyacceptable carriers include but are not limited to water,salt-solutions, alcohol, vegetable oils, polyethylene glycols, gelatin,lactose, amylose, magnesium stearate, talc, silicic acid, viscousparaffin, perfume oil, fatty acid monoglycerides and diglycerides,petroethral fatty acid esters, hydroxymethyl-cellulose,polyvinylpyrrolidone, etc.

[0084] The pharmaceutical preparations can be sterilised and if desiredmixed with auxiliary agents, e.g., lubricants, preservatives,stabilisers, wetting agents, emulsifiers, salts for influencing osmoticpressure, buffers, colourings, flavourings and/or aromatic substancesand the like which do not deleteriously react with the compounds of theinvention.

[0085] The compounds of the invention may be administered alone or incombination with: pharmaceuticall acceptable, carriers or diluents. Thecompounds of the invention may be administered via oral, parenteral ortopical routes. The administration may be carried out in single ormultiple doses. The compounds of the invention may be administered in awide variety of different dosage forms, for example they may be combinedwith various pharmaceutically acceptable, inert carriers in the form oftablets, capsules, lozenges, troches, hard candies, powders, sprays,creams, salves, suppositories, jellies, gels, pastes, lotions,ointments, aqueous suspensions, injectable solutions, elixirs, syrups,and the like. Such carriers include solid diluents or fillers, sterileaqueous media and various non-toxic organic solvents, etc. Moreover,oral pharmaceutical compositions may be sweetened and/or flavoured. Ingeneral, the compounds of the invention are present in such dosage formsat concentration levels ranging from about 5.0%, to about 70% by weight.

[0086] For oral administration, tablets may contain various excipientssuch as microcrystalline cellulose, sodium citrate, calcium carbonate,dicalcium phosphate and glycine may be employed along with variousdisintegrants such as starch (and preferably corn, potato or tapiocastarch), alginic acid and certain complex silicates, together withgranulation binders like polyvinylpyrrolidone, sucrose, gelatin andacacia. Additionally, lubricating agents such as magnesium stearate,sodium lauryl sulphate and talc may be employed. Solid compositions of asimilar type may also be employed as fillers in gelatin capsules;preferred materials in this connection also include lactose or milksugar as well as high molecular weight polyethylene glycols. Whenaqueous suspensions and/or elixirs are desired for oral administration,the active ingredient may be combined with various sweetening orflavouring agents, colouring matter or dyes, and, if so desired,emulsifying and/or suspending agents, together with diluents such aswater, ethanol, propylene glycol, glycerin and various combinationsthereof.

[0087] For parenteral administration (including intraperitonealsubcutaneous, intravenous, intradermal or intramuscular injection),solutions of compounds of the invention in either sesame or peanut oilor in aqueous propylene glycol may be employed. The aqueous solutionsmay be buffered if necessary and the liquid diluent first renderedisotonic. These aqueous solutions are suitable for intravenous injectionpurposes. The oily solutions are suitable for intraarticular,intramuscular and subcutaneous injection purposes. The preparation ofall these solutions under sterile conditions is readily accomplished bystandard pharmaceutical techniques well known to those skilled in theart. For parenteral administration, examples of suitable preparationsinclude solutions, preferablyoily or aqueous solutions as well assuspensions, emulsions, or implants, including suppositories. Compoundsof the invention may be formulated in sterile form in multiple or singledose formats. For example the compounds of the invention may bedispersed in a fluid carrier such as sterile saline or 5% salinedextrose solutions commonly used with injectables.

[0088] The compounds of the invention may be administered topically forexample when treating inflammatory conditions of the skin. Examples ofmethods of topical administration include transdermal, buccal, orsublingual application. For topical applications, therapeutic compoundscan be suitably admixed in a pharmacologically inert topical carriersuch as a gel, an ointment, a lotion or a cream. Such topical carriersinclude water, glycerol, alcohol, propylene glycol, fatty alcohols,triglycerides, fatty acid esters, or mineral oils. Other possibletopical carriers are liquid petrolatum, isopropylpalmitate, polyethyleneglycol, ethanol 95%, polyoxyethylene monolauriate 5% in water, sodiumlauryl sulphate 5% in water, and the like. In addition, materials suchas anti-oxidants, humectants, viscosity stabilisers and the like alsomay be added if desired.

[0089] For enteral application, particularly, suitable are tablets,dragees or capsules having talc and/or carbohydrate carrier binder orthe like, the carrier preferably being lactose and/or cornstarch and/orpotato starch. A syrup, elixir or the like can be used wherein asweetened vehicle is employed. Sustained release compositions can beformulated including those wherein the active component is protectedwith differentially degradable coatings, e.g., by microencapsulation,multiple coatings, etc.

[0090] In addition to treatment of human subjects, the therapeuticmethods of the invention also will have significant veterinaryapplications, e.g. for treatment of livestock such as cattle, sheep,goats, cows, swine and the like; poultry such as chickens, ducks, geese,turkeys and the like; horses; and pets such as dogs and cats.

[0091] It will be appreciated that the actual amount of the compound ofthe invention used in a given therapy will vary according to thespecific compound being utilised, the particular compositionsformulated, the mode of application, the particular site ofadministration, etc. Optimal administration rates for a given protocolof administration can be readily ascertained by those skilled in the artwithout undue burden.

[0092] In general, compounds of the invention for treatment can beadministered to a subject in dosages used in prior tetracyclinetherapies. See, for example, the Physicians' Desk Reference. Forexample, a suitable effective dose of one or more compounds of theinvention will be in the range of from 0.01 to 100 more milligrams perkilogram of body weight of recipient per day, preferably in the range offrom 0.1 to 50 milligrams per kilogram body weight of recipient per day,more preferably in the range of 1 to 20 milligrams per kilogram bodyweight of recipient per day. The desired dose is suitably administeredonce daily, or several sub-doses, e.g. 2 to 5 sub-doses, areadministered at appropriate intervals through the day, or otherappropriate schedule.

[0093] It will also be understood that normal, conventionally knownprecautions will be taken regarding the administration of tetracyclinesgenerally to ensure their efficacy under normal use circumstances.Especially when employed for therapeutic treatment of humans and animalsin vivo, the practitioner should take all sensible precautions to avoidconventionally known contradictions and toxic effects. Thus, theconventionally recognised adverse reactions of gastrointestinal distressand inflammations, the renal toxicity, hypersensitivity reactions,changes in blood, and impairment of absorption through aluminium,calcium, and magnesium ions should be duly considered in theconventional manner.

[0094] The compounds and pharmaceutical compositions of the inventionmay be administered alone or in combination with other known compoundsand compositions for treating tetracycline compound responsive states ina mammal e.g. a human. The term in combination with a known compound orcomposition is intended to include simultaneous, concomitant andsequential administration.

[0095] Accordingly, the present invention provides a combinationcomprising a compound of formula (I) or a pharmaceutically acceptablederivative or solvate thereof, and a further active ingredient suitablefor treating tetracycline compound responsive states in a mammal e.g. ahuman.

[0096] Compounds of Formula (I) and pharmaceutically acceptablederivatives and solvates thereof may be prepared by general methodsoutlined hereinafter where the groups R, R¹, R¹ and R³ have the meaningdefined for compounds of formula (I) unless otherwise stated.

[0097] The invention will now-be illustrated by way of the followingExamples which should not be construed as constituting a limitationthereto.

[0098] Compounds of Formula (I) and pharmaceutically acceptablederivatives and solvates thereof may be prepared by general methodsoutlined hereinafter where the groups R, R¹, R² and R³ have the meaningdefined for compounds of formula (I) unless otherwise stated.

[0099] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is a pyrrolering optionally substituted by one or more group R or a pharmaceuticallyacceptable derivative or solvate thereof which process comprisesreacting a compound of formula (II) with a compound of formula (III)wherein Ra and Rb are hydrogen or C₁₋₆ alkyl under dehydratingconditions for example in the presence of sulphuric acid in methanol.

[0100] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is a pyrrolering optionally substituted by one or more group CHNORa or apharmaceutically acceptable derivative or solvate thereof which processcomprises reacting a compound of formula (IV) with NH₂ORa in water.

[0101] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is a pyrrolering optionally substituted by one or more group cyano or apharmaceutically acceptable derivative or solvate thereof which processcomprises reacting a compound of formula (V) with acetic anhydride andformic acid.

[0102] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is a pyrrolering optionally substituted by one or more group CH₂NRaRb or apharmaceutically acceptable derivative or solvate thereof which processcomprises reacting a compound of fomula (IV) with NHRaRb underdehydrating conditions for example in the presence of acetic acid,methanol and water and then subjecting the product to a reducing agentsuch as sodium cyanoborohydride.

[0103] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is atetrazole ring or a pharmaceutically acceptable derivative or solvatethereof which process comprises reacting a compound of fomula (II) withisobutyl nitrite in methanolic hydrochloric acid followed by treatmentwith a mixture containing sodium azide and triethyl orthoformate inacetic acid.

[0104] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (I) wherein A is a.1,23-triazole ring optionally substituted by one or more group CO₂Ra ora pharmaceutically acceptable derivative or solvate thereof whichprocess comprises reacting a compound of formula (II) with isobutylnitrite in methanolic hydrochloric acid followed by treatment withsodium azide to afford the corresponding 7-azido intermediate, and thensubjecting the 7-azido intermediate to a reaction with alkylpropiolatein dioxane under reflux conditions.

[0105] According to a further aspect of the invention, there is provideda process for preparing a compound of Formula (II) by reacting acompound of formula (VI) with dibenzyl azodicarboxylate intrifluoroacetic acid and further reduction e.g. hydrogen in methanol andsulphuric acid.

[0106] Compound VI is referenced in Current Pharmaceutical Design 1998 4119-132. Compounds of formula III are available as commercial startingmaterials or synthesis would be apparent to a skilled person.

[0107] The invention will now be illustrated by the following Exampleswhich should not be construed as constituting a limitation thereto.

[0108] Growth inhibitory activity was determined on liquid medium by theantibiotic dilution technique using 96-well microtiter system platescontaining two-fold dilutions of antibiotic-agent in 0.2 ml. ofMueller-Hinton broth. Plates were inoculated with each test organism toyield a final inoculum of 5×10⁵ CFU/ml and were incubated aerobically at37° C. for 18 h. The MIC was defined as the lowest concentration ofantibacterial agent that inhibited development of visible growth in themicrodilution wells. GAR936 can be prepared e.g. as in J. Med Chem 1994,37 184-188. Minocyline is available from e.g. Aldrich.

BIOLOGICAL EXAMPLES

[0109] 7-pyrrol derivatives Compound A Compound B Compound C GAR-936MINO S. aureus ATCC 29213 0.015 0.015 0.125 0.5 0.03 S. aureus GFX01596Tet R 0.5 0.25 4 1 0.12 S. pneumoniae 157 0.015 0.015 0.015 0.25 0.5 S.pneumoniae GFX01778 Tet R 2 2 0.03 0.06 16 E. faecalis ATCC 29212 2 20.125 0.5 2 E. faecalis 73 Tet R 4 8 0.004 0.5 32 E. faecium 494 8 320.25 0.5 32 F. faecium 97 Tet R 8 >128 0.06 0.5 32 H. influenzae ATCC4927 0.5 1 1 1 0.5 M. catarrhalis ATCC 23246 0.001 0.008 0.002 0.120.001 E. coli 851E 1 1 1 1 0.5 E. coli 851ML308-225 0.5 0.5 0.03 0.25 E.coli D1-209 Tet R 16 >128 1 0.5 16 E. coli D1-299 Tet R 4 32 16 0.5 1 K.Pneumoniae 3226 >128 >128 125 2 32 P. aeruginosa 3808 >128 >128 32 32 16A. calcoaceticus 1726 8 >128 16 32 1

[0110] Comparator Compounds.

[0111][4S-(4aα,5aα,12aα)]-4-(Dimethylamino)-7-(1H-pyrrol-1-yl-3-carboxaldehyde)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide(Compound B)

[0112] A mixture of 2,5-dimethoxy-3-tetrahydrofurancarboxaldehyde (0.35ml) and 2.5M sulfuric acid (1.2 ml) was added dropwise to an open vesselcontaining a methanolic solution (10 ml) of[4S-(4aα,5aα,12aα)]-7-(Amino)-4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide(U.S. Pat. No. 3,403,179) (0.6 g) and stirred at room temperature for 2h. The reaction mixture was precipitated in cold ether and filtrate togive a brown residue which was dissolved in water, freeze andlyophilised. The residue was purified using C18-F40 Biotage columnchromatography. Pure compound (0.425 g) was obtained afterlyophilisation of the appropriate fractions.

[0113][4S-(4aα,5aα,12aα)]-7-(3-Cyanopyrrol-1-yl)-4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide(Compound A)

[0114] A water solution (12 ml) of carboxaldehyde (0.17 g) was stirredfor 2h in the presence of a two fold excess of hydroxylaminehydrochloride. The reaction mixture was freeze and lyophilised and thenfiltrate on RP2 silica gel to give a 1:3 mixture of syn:anti isomers ofthe oxime in quantitative yield.

[0115] Then, the oxime (0.06 g) in a 1:1 mixture of acetic anhydride andformic acid (4 ml) was stirred at 90° C. for 2h. The reaction mixture atroom temperature was precipitated in cold ether and filtrate to give abrown residue which was dissolved in water, freeze and lyophilised. Theresidue was purified using a C8 Luna semi-preparative HPLC to give purenitrile (0.027 g) as a yellow powder after lyophilisation of theappropriate fractions.

[0116] H-RMN (CD₃OD) 7.49(bt, 1H, H-2pyrrole), 7.47(d, 1H, H-8, J=8.7Hz), 6.95(d, 1H, H-9), 6.90(dd, 1H, H-5pyrrole, J=2.1 and 2.8 Hz),6.58(dd, 1H, H-4pyrrole, J=1.6 and 2.8 Hz), 4.01(bs, 1H, H-4).

[0117] MS (e.s.+): m/z 505.3 (M⁺+H).

EXAMPLE

[0118][4S-(4aα,5aα,12aα)]-7-(Amino)-4-(dimethylamino)-9-[[(N,N,-dimethylamino)acetyl]-amino]-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide

[0119] A 0.3 g, portion of[4S-(4aα,5aα,12aα)]-4-(dimethylamino)-9-[[(N,N,-dimethylamino)acetyl]-amino]-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamidewas dissolved in 7 ml of trifluoroacetic acid. The solution was cooledto 0° C. to 4° C. in a water-ethanol bath and 0.5 g of dibenzylazodicarboxylate were added by portions. The mixture was stirred for 24huntil the reaction was completed. The trifluoroacetic acid wasevaporated at room temperature under vacuum. The residue was dissolvedin 2 ml of methanol and precipitated in 400 ml of cold ether. Filtrationgave 0.34 g of a yellow solid.

[0120] MS (e.s.+): m/z 813 (M⁺+H).

[0121] A 0.3 g portion of this compound was mixed with 0.06 g of 10% Pdon carbon, in 15 ml of 1N H₂SO₄ in methanol. The mixture was reduced for15 hours at 35 Psi hydrogen pressure in a Parr apparatus. The catalystwas filtered off and washed with methanol. The filtrate were combinedwith the washings and concentrated. The residue was dissolved in 10 mlof methanol and precipitated in 500 ml of cold ether and filtrate togive 0.24 g of a residue which was purified in a semipreparative HPLCsystem in a C8 Luna column. The appropriate fractions were combined andlyophilised to give 0.22 g of pure compound as a yellow solid.

[0122] H-RMN (CD₃OD) 8.57(s, 1H, H-8), 4.27(s, 2H, CH₂), 4.11 (bs, 1H,H-4), 3.01 (s, 12H, 4CH₃N).

[0123] MS (e.s.+): m/z 530.15 (M⁺+H)

[0124]4S-(4aα,5aα,12aα)]-7-(1H-pyrrol-1-yl-3-carboxaldehyde)-4-(dimethylamino)-9-[[(N,N,-dimethylamino)acetyl]-amino]-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide(Compound C)

[0125] A mixture of 2,5-dimethoxy-3-tetrahydrofurancarboxaldehyde (0.05ml) and 2.5M sulfuric acid (0.12 ml) was added dropwise to an openvessel containing a methanolic solution (1 ml) of the above compound(M198/191/1) (0.06 g) and stirred at room temperature for 2 h. Thereaction mixture was precipitated in cold ether and filtrate to give abrown residue which was dissolved in water, freeze and lyophilised. Theresidue was purified using C8-Luna semipreparative HPLC. Pure compound(0.025 g) was obtained after lyophilisation of the appropriatefractions.

[0126] H-RMN (CD₃OD-DC1) 9.71 (s, 1H, CHO), 8.35(s, 1H, H-8), 7.67(bt,1H, H-2pyrrole), 6.93(m, 1H, H-5pyrrole), 6.71(m, 1H, H-4pyrrole), 4.29,(s, 2H, CH₂), 4.11(bs, 1H, H-4), 3.0 (s, 12H, 4CH₃N)

[0127] MS (e.s.+): m/z 508.15 (M⁺+H)

[0128] The application of which this description and claims forms partmay be used as a basis for priority in respect of any subsequentapplication. The claims of such subsequent application may be directedto any novel feature or combination of features described herein. Theymay take the form of product, composition, process or use claims and mayinclude, by way of example and without limitation, one or more of thefollowing claims:

1. A compound of formula (I):

wherein: A represents an aromatic 5 membered heterocycle, optionallycontaining, in addition to the nitrogen atom indicated in formula (I),one to three additional nitrogen atoms and optionally substituted by oneor more groups “R” selected from halogen, —NRaRb, C₁₋₆ alkyl, C₂₋₆alkenyl, C₃₋₆ alkynyl, aryl, heteroaryl, hydroxy, —OC₁₋₆ alkyl, formyl,cyano, trifluoromethyl, —CHNORa, —CO₂Ra, —CONRaRb, —NRaC(O)Ra,—NRaC(O)ORa, —OC(O)NRaRb, —OC(O)Ra, —OC(O)ORa, or a C₁₋₆ alkyl groupsubstituted by one or more groups selected from hydroxy, —NRaRb,—OC₁₋₆alkyl, —SRa, —CHNORa, —CO₂Ra, —CONRaRb, —NRaC(O)Ra, —NRaC(O)ORa,—OC(O)NRaRb, —OC(O)Ra, —OC(O)ORa X represents —NRxRy or —OC₁₋₆ alkyloptionally substituted by one or more groups selected from hydroxy,methoxy, halogen, amino and trifluoromethyl. Ra and Rb independentlyrepresent hydrogen or C₁₋₆ alkyl (preferably methyl); R¹ representshydrogen, C₁₋₆ alkyl or together R¹ and R² represent a CH₂ moiety; R²represents hydrogen, —OC₁₋₆ alkyl, —O(O)C₁₋₆ alkyl or hydroxy; R³represents hydrogen, hydroxy or together R³ and R¹ represent a CH₂moiety; R⁴ represents hydrogen, or C₁₋₆ alkyl, optionally substituted byone or more groups selected from hydroxy, methoxy, halogen, amino andtrifluoromethyl; Rx and Ry independently represent hydrogen, benzyl,C₃₋₆cycloalkyl, C₃₋₆alkenyl, C₃₋₆alkynyl, C₁₋₆ alkyl optionallysubstituted by one or more groups selected from hydroxy, methoxy,halogen, NRaRb and trifluoromethyl, —C₁₋₆ alkylcycloalkyl, —C₁₋₆alkylheterocycle, C₁₋₆ alkylamino and C₁₋₆ alkylthio or together Rx andRy form a heterocycle; and pharmaceutically acceptable derivatives andsolvates thereof.
 2. A method for the treatment of a tetracyclinecompound responsive state in a subject, preferably a human, whichcomprises administering to the subject an effective amount of a compoundof formula (I) or pharmaceutically acceptable derivative or solvatethereof.
 3. A compound of formula (I) or a pharmaceutically acceptablederivative or solvate thereof, for use in medical therapy.
 4. Use of acompound of formula (I) or a pharmaceutically acceptable derivative orsolvate thereof for the manufacture of a medicament for the treatment ofa tetracycline compound responsive state.
 5. A pharmaceuticalformulation comprising a compound of formula (I) or a pharmaceuticallyacceptable derivative or solvate thereof, and one or morepharmaceutically acceptable carriers.